GhostCode: Device Code Auth to Microsoft Authentication Broker

Ibrahim Saud@tektrix

•updated Sep 17, 2026•0•0•3

Detects network requests to the Microsoft authentication service specifically targeting the /common/oauth2/deviceauth endpoint, which is used in the OAuth 2.0 Device Authorization Grant flow. While legitimate for device authentication (e.g., CLI tools, smart devices), this flow can be abused by adversaries for phishing attacks to bypass traditional credential-based MFA, allowing them to gain persistent access to a user account once the target authorizes the code.